1. Field of the Invention
This invention relates to the improvement in stride resulting from an energy efficient device added to the bottom of a one's foot, by providing increased comfort, by allowing one to attain a stable increased stride, by preventing fatigue, by either permanently or temporarily attaching the device to footwear or temporarily to an unshoed foot, by the bending of a cantilevered leaf spring to store energy during a stride resulting from the application of one's weight and then by the release of that stored energy in the cantilevered leaf spring to assist the user in completing a longer than normal stride.
2. Description of Prior Art
Over the years various efforts have been made to improve one's stride by adding to or incorporating into footwear energy storage and energy releasing devices. The purpose of such devices was to provide a means of increasing the efficiency of one's stride by allowing for an increase in stride or by making the stride more comfortable. Such prior art was directed to absorbing vertically directed energy to then utilizing that absorbed energy in assisting locomotion. However, such footwear devices are either too complicated to economically manufacture, too unstable in use to be sold to the public, too heavey for practical use or too uncomfortable to use for a reasonable length of time. In addition many devices previously proposed must be incorporated into footwear at time of manufacture. Thus, such devices cannot be temporarily used with normally made footwear and none can be used with no footwear at all.
For example, U.S. Pat. No. 4,660,299 to Omilusik is directed to the use of four relatively long coil springs affixed to a platform resting beneath the footwear. Two such springs are located beneath the location of one's heel. While the remaining two coil springs are positioned at a forward location beneath the footwear. In taking a stride the rear most located two springs first make contact with the supporting surface and are compressed by one's weight to absorb some of the energy. As the user moves forward subsequently more energy of the stride is absorbed by the forwardly located coil springs. In completing the stride this absorbed energy is released and can increase one's stride as well as provide comfort for the user. However, since each coil spring affixed to the platform acts independent of its neighboring spring release of the stored energy can be misdirected. Further, since each spring has a small bending moment one's footwear cannot always maintain the properly desired orientation relative to the supporting surface below. Such action would particularly noticeable on ruff terrain. As a result in use the direction of one's travel can be haphazardly altered and the stability of one's vertical stance can be compromised. Thus, use of this device is hazardous to the wearer.
U.S. Pat. No. 4,267,648 to Weisz is directed to an arrangment of relatively short springs disposed within the sole and heel of footwear. The collection of springs separates a bottom movable section of the sole from a load bearing membrane directly beneath and next to the user's foot. Because of the relative short length of the springs during locomotion energy is returned to the wearer only during a very small portion of the stride. Thus, only a small increase in stride can be realized. It is further noted that said invention cannot be used with existing normally manufactured footwaer or without the use of any footwear.
U.S. Pat. No. 5,042,175 to Ronen et. al. discloses a user-specific inner sole spring arrangement to be inserted into a footwear. The invention can also be prefabricated into the sole of footwear. The preferred embodiment of the invention is a coil spring system customized principly to provide comfort to the wearer. The system can also provide increase in stride by absorbing and releasing some of the energy normally expended in locomotion. However, because of limited space in footwear a higher inner sole cannot be used to increase the stide. Further, no claim is made for said Patent to be used with no footwear.
U.S. Pat. No. 4,936,030 to Rennex addresses the problem of comfort to the wearer of footwear as well as to the method of absorbing energy of locomotion and releasing the absorb energy by the use of mechanical devices of levers and hydraulic fluids. It would be uneconomical to manufecture this invention plus as was disclosed in the Patent itself the added weight of the device presents a problem to the wearer. No claim is made to use said device without footwear.
U.S. Pat. No. 4,843,737 is directed to the use of an elliptical spring device disposed within the heel portion of footwear. The purpose of the invention is to provide both comfort to the wearer by absorbing the shock of heel impact with terrain and by the release of that energy to allow the user to expend less energy during activity. Since the major thrust for locomotion comes from forces located at the ball of a foot rather than the heel area this invention does lttle to help increase the stride. Further no claim is addressed to the use of said device without footwear.
U.S. Pat. No. 4,881,329 to Crowley is directed to a spring generally oval-shaped disposed within the midsole area of athletic footwear. Since the major thrust for locomotion comes from forces located at the ball of a foot rather than the midsole region this invention does little to help increase the stride. Further no claim is made to use said device without footwear.
U.S. Pat. No. 4,858,338 to Schmid is directed to the use of an insert of an elastic material disposed within a sole of a shoe to absorb, store and return kinectic energy to the wearer. The invention is not designed to increase comfort to the wearer. Positioning the energy absorbing etc. device directly beneath the sole of the wearer as in the invention can utilize some of the energy stored as the result of impact with terrain and can propel the user to yield an increase in stride. However the action of the flexible insert imbedded within the sole during use applies a force downward on the heel portion of the footwear. Thus, to prevent the heel of the footwear from falling off the foot the force is transmitted to the lacing of the footwear resulting in undue stress on the instep and unecessary chafing of skin at the instep.